Electromyogram-gas cystometrogram: its use in the management of neurogenic bladder of spinal cord injury

The electromyogram (emg)-gas cystometrogram was used to study spinal-cord-injured patients with indwelling catheters before trial of voiding (TOV) to remove an indwelling catheter. Twenty-four patients were studied during 27 consecutive admissions. A coaxial needle electrode was placed in the external urethral sphincter. The output of a cystometer was simultaneously recorded on the emg printout so that the relationship of the shpincter response to distention of the bladder could be observed. Of 10 patients without bladder contractions, 7 had active urethral sphincters and 6 of these failed to achieve less than 50 ml residual thereby failing the TOV. The seventh patient succeeded in the trial and on subsequent study was found to have developed bladder contractions with a coordinated bladder-sphincter synergy. The 3 patients without bladder contractions or sphincter activity succeeded in their TOV using Credé's method. Seventeen patients with bladder contractions were divided into synergic, nonsynergic and partially synergic patterns. The 3 patients with synergic patterns succeeded in their TOV. Thirteen of 14 nonsynergic or partially synergic patients failed the TOV. The 1 nonsynergic patient who succeeded had bladder contractions of 70 cm of water compared to a mean of 28 cm of water for all other patients with bladder contraction. The emg-gas cystometrogram was helpful in selecting those patients who were successful in removing the Foley catheter. Important factors governing success in the multiple effort trial of voiding were the amplitude of the detrusor contraction, the presence of detrusor-sphincter synergy and the presence of a flaccid sphincter.